Welcome

The title says it all: this blog features physics videos found everywhere on the web: animations, demonstrations, lectures, documentaries.

Please go here if you want to suggest other nice physics videos, and here if I mistakingly infringed your copyrights. If you understand French, you'll find a huge selection of physics videos in French in my other blog Vidéos de Physique.

Friday, 28 September 2012

A NASA spacecraft has recorded eerie-sounding radio emissions coming from our own planet. These beautiful "songs of Earth" could, ironically, be responsible for the proliferation of deadly electrons in the Van Allen Belts.

What happens when you decrease the pressure around a liquid? It boils. Water boils at room temperature once the pressure is low enough. What is interesting is that this decreases the temperature of the liquid. The fastest molecules escape, leaving the slower ones behind.
Using this trick with liquid nitrogen, it is possible to create solid nitrogen at a temperature of -210C. We then poured the solid and liquid nitrogen mixture onto a tray of water. The surface of the water became so cold that CO2 solidified out of the atmosphere on its surface. Then, since CO2 does not pass through the liquid phase at atmospheric pressure, it was propelled on the water surface by jets of gas as it sublimed.
Huge thanks to the Palais de la Decouverte.
Music by Kevin MacLeod of Incompetech.com (Mirage)

Friday, 21 September 2012

Hank tells us about new research into the question of how animals navigate from place to place - while the problem is still unresolved, we do have some hypotheses, and they all involve something called "magnetoreception."

Monday, 17 September 2012

Following the announcement of the discovery of a new particle made at CERN on July 4, this piece of videonews from CERN explains what is missing to declare that the new boson found at the LHC is actually the Higgs or not and that to finally answer that question precise measurements of the spin of the newly found particle have to be made. Contains interviews to CMS Higgs Searches co-convener, Christopher Pauss and theoretician John Ellis.

Thursday, 13 September 2012

An astonishing 99.6% of our Universe is dark. Observations indicate that the Universe consists of 70% of a mysterious dark energy and 25% of a yet unidentified dark matter component, and only 0.4% of the remaining ordinary matter is visible. Understanding the physics of this dark sector is the foremost challenge in cosmology today. Sophisticated simulations of the evolution of the Universe play a crucial task in this endeavor.

Wednesday, 12 September 2012

Is a flame really a plasma? Well it depends on your definition of plasma, but there are certainly ions in a flame, formed as molecules collide with each other at high speed, sometimes knocking electrons off of their atoms.
Special thanks to the Palais de la Decouverte for helping me perform this experiment. Using tens of thousands of volts on two metal plates, we created a strong electric field around the plasma. This pulled positive ions in one direction and negative ions in the other direction elongating the flame horizontally and causing it to flicker like a "papillon" (butterfly). Then we showed that much longer sparks can be made through the flame than through air since the ions increase the conductivity.

In this edition of IDTIMWYTIM, Hank explains why the common understanding of "equinox" is wrong, what the equinox actually is, and then rages a little against astronomers and their stupid confusing Latin terms.

Physics, anyone? In this segment, Dr. Ainissa Ramirez discusses how the strings in a tennis racket--often made of synthetic or natural materials--make the important topspin shot possible. She shows how knowing physics can give your game an advantage.

"I Don't Think It Means What You Think It Means" examines scientific theories that have taken on a life of their own in popular culture & we help you understand what they really mean in scientific terms. Today we take on Schrodinger's Cat, the famous thought experiment by Austrian physicist Erwin Schrodinger.

Neutrinos are a mystery to physicists. They exist in three different flavors and mass states and may be able to give hints about the origins of the matter-dominated universe. A new long-baseline experiment led by Fermilab called NOvA may provide some answers.

Tuesday, 4 September 2012

The Large Hadron Collider is famous for its size (17 miles in circumference), its cost (more than 7 billion euros), and accomplishments (the discovery of the Higgs boson chief among them).
SLAC's two-mile-long linear accelerator could be considered the LHC of its day -- 50 years ago.

In this video, recorded during the Aug. 24, 2012, symposium commemorating those 50 years, Frank Zimmerman of CERN gives a crash course on the history of particle colliders, from the first cyclotron, built by Ernest Lawrence and his graduate student Stanley Livingston in 1931 (that could fit in the palm of a hand), to CERN's nation-spanning behemoth. He also lets the audience in on his own secret master plan for ever more powerful accelerators -- not just at CERN, but at SLAC.

Sunday, 2 September 2012

Two identical tuning forks and sounding boxes are placed next to one another. Striking one tuning fork will cause the other to resonate at the same frequency. When a weight is attached to one tuning fork, they are no longer identical. Thus, one will not cause the other to resonate. When two different tuning forks are struck at the same time, the interference of their pitches produces beats.